Method of reducing metallic oxids with metallic aluminium.



PATENTED APR.K14, 1903.

. I'. 0. W EBER METHOD 0F REDUCING METALLIGv OXIDS WITH METALLICALUMINIUM.

APPLICATION FILED AUG. 6, 1902.

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UNITED STATES PATENT OEEICE.

FREDERICK C. WEBER, OF CHICAGO, ILLINOIS.

METHOD F REDUCING METALLlC OXIDS WITH METALLIC VALUMINIUM.

y SPECIFICATION forming part of Letters Patent No. 725,520, dated April14, 1903.

l v Application filed August 6, 1902. Serial No. 118,585. (No specimens)To tl/f who/2t t may concern:

Be it known that I, FREDERICK C. WEBER, a citizen of the United States,residing at Chicago, in the county of Cookand State of Illinois, haveinvented or discovered a certain new and useful Improvement in Methodsof Reducing Metallic Oxids with Metallic Aluminium, of which thefollowing is a specification, the same being an improvement on themethod of reducing `metallic oxids with me' ltallic aluminium of myapplication, Serial No. 555,990, filed April l5, 1901.

The employment of aluminium and the reducing action thereof for thetreatment of metallic oxids in the production of metals and alloys iswell known, and various methods have been devised for effecting suchreduction; but it has been found in practice that in the reduction ofthe oxids of metals and of metalloids employing aluminium as thereducing agent the reaction always so occurs that caloric is set free asthe resultant effect,

,the latent caloric of the components of the found in the treating ofmetallic oXids with.

aluminium is the danger of an rexplosion of the charge, and the cause ofthe explosion may be either due to the instantaneous reaction or fromthe presence of a triie of moisture, which latter is due to and derivedfrom the hygroscopic character of some of the oxids used and which isfound present in the shape of water of crystallization and hygroscopicor ordinarily present moisture'. The heat produced by these reductionsis so intense that all ordinarily present moisture is instantaneouslyconverted into steam, which acts with all the suddenness and power of ahigh explosive. The successful. treatment of metallic oxidswith'aluminiuni requires in order tol prevent explosions the removal ofall hygroscopic or ordinarily present moisture in the mixture before the'final treatment by the aluminium, and this removal of the moisturefound in the charge constitutes the essential and important step incarrying out the process of my invention, and combined with this step isthat of employing for the charge the combination of aluminium andmetallic oxids in the form of a very fine powder or in granules of suchfineness that the time required for each separated particle orgranule'to become heated to the ytemperature where the reaction isinitiated shall be approximately uniform and correct, andthistemperature varies from 200 Fahrenheit for producing metallicmanganese to 300O Fahrenheit and over for producing metallic chromium orthe titanium compounds, so that after the reaction is initiated suchreaction will progress at just the right speed for perfect reduction,and thereby have the resulting product which `it is aimed to" obtaincorrectly produced whether it be a separation of the produced metal fromthe corundum or the formation of the new chemical molecule and itsproper separation from. the corundum-slag.

Briefly stated, then, the object of the process of this invention is theremoval of all hygroscopic or ordinarily present moisture, thus bringingthe charge into a condition for reaction Without danger of explosion;and the invention consists in the employment of materials for the chargeunder conditions hereinafter described and subjected to the action ofheat for the removal of all moisture, as here-v inafter described andclaimed. y

In carrying out the method or process of my invention the charge to betreated is composed of finely powdered or comminuted metallic oXid andaluminium mixed together under conditions of chemical equivalents. Thischarge of oXid and aluminium is to be subjected to a sufficient heatthat will remove all moisture, leaving the charge free of moisture andin condition for further treatment for reducing purposes. The heater anddrier-preferably utilized for the drying-out step of the charge is inthe form of a rectangular box having'an inner wall or shell and an outerwall or shell, interposed between which walls `or shells is a filling ofa suitable non-conduc- IOO tor of heat-such as, for instance, asbestosboiler covering. The heating chamber is within the interior shell orcasing, and this shell or casing, at the bottom thereof, has locatedtherein a coiled steam-pipe, or preferably a plate of type-metal coveredby a thick plate ot' sheet-iron, the type-metal plate having therein afiat coil of brass pipe so closely coiled that the molten type-metalwilljust fully cover the brass pipe, leaving the ends of the pipe projectingfor connection with a steam supply and eduetion pipe for passing steamthrough the coil to fully dry any oxid placed upon the plate within thechamber. The temperature for drying out the material must be high enoughto eit'ectually drive oft all the moisture contained in the material andat the same time must not be so high as to cause any reaction within thedrying-chamber, and a proper temperature would be obtained with steam atone hundred and twenty pounds pressure, which would give a teinperatureof over 250D Fahrenheit, and with this degree of heat the full drying ofthe charge is attained, and no reaction is initiated.

The preferred form of heater and drier is shown in the drawings, inwhich* Figure l is a front elevation of the heater and drier with thedoor closed; Fig. 2, a crosssectional plan view showing the bottom ofthe drying-chamber provided with a coil of pipe; and Fig. 3, a sectionalelevation fore and aft of the heater and drier, showing the doorpartially open.

The heater and drier has an outer box or casing A and an inner box orcasing B, each box or casing preferably made of sheet-iron, though othersuitable metal or materials lnay be used. The space between the wall (tof the outer box or casing and the wall l) of the inner box or casing isfilled with any suitable material that is a non-conductor of heat, whichmaterial d, wholly incloses the inner box or casing on the top sides andends and a portion of the front, the front having a door C, hinged atits lower end, as shown, by a suitable hinge c, and having a knob orhaudle c', by means of which the door can be opened to place thematerial within the chamber of the inner box or casing, and when thematerial is in place the door is closed, retaining the heat within thechamber. The bottom of the inner box or casing has a plate D, preferablyof type-metal, below which is a filling or covering of a non-conductorof heat and over which is a covering of sheet-iron and in which iscontained a coil E for the transmission of steam through the coil toheat the chamber of the inner box or casing, and, as shown, the ends ofthe coil E project beyond the front of the outer box or casing, and eachend is provided with a shut-od valve c for controlling the admission anddischarge of steam. The material is placed within the chamber of theinner box or casing and the door closed, after which steam is admittedto the coil E for the steam to act and produce the required amount ofheat for elfectually removing all moisture from the charge. The materialplaced in the chamber is a mixture of aluminium and the to-betreatedmetallic oxids, both of which are required in the form of a iine powderor granules, as is called for in each separate operation of reaction.

The material placed within the chamber of the inner box or casing andtreated to the required degree of heat for removing all hygroscopic orordinarily present moisture is ready, after the drying operation isfinished, to be placed in a crucible or other vessel, where it issubjected to further treatment by which the entire charge will bebrought to a heat, either by means of an electric current or otherwise,having a suiiicient intensity to melt the aluminium for the melted aluminium to react with the finely powdered or granuled oxid or oxids,bringing the entire charge under full reaction, producing in a fewmoments molten corundum, which makes its appearance on the surface,while a regulus of the metal of the oxid or alloy which is undergoingreaction forms at the bottom of the crucible or other vessel. It is tohe understood that a series of the heaters and driers can be arranged sothat the fully-dried charge from each receptacle can be fed into thecrucible or other vessel in succession, the crucible being provided withholes for tapping and being emptied after the contents of a heater anddrier have been processed or treated for the reduction required, andwhen emptied the mixture or contents of another heater and drier can beemptied or passed into the crucible or other vessel.

The preparatory treatment of heating and drying the charge before thereaction takes place avoids all danger of explosion, and consequentlyinjury and loss, enables a powdered or grauuled aluminium and a metallicoxid to be electually mixed and treated with all of the moistureremoved, and the process of preparatory treatment of the charge beforereaction results in a production of a more perfect and uniform resultantto be obtained.

The reduction of manganese oxids in the form of powder or granules canbe practically attained with material which will pass through aneight-mesh sieve; but for the reduction of titanium oxid in a form ofpowder or granules the material should pass through aone-hundred-and-twenty-mesh sieve for obtaining the best resultants, andthe mesh of sieves to suit the various metallic oxids and the oxids ofthe metalloids-boron and silicon-should range between these two ex`tremes of eight and one hundred and twenty for giving the best reactionand the most perfect results. This preparatory heating and drying toremove all the moisture has been successfully applied by me withmetallic oxids and oxids of metalloids having one metal as the base andalso with oxids having two IIC metals as the base, and in both cases theresult has been the reduction of the oxids, and this is also trueWith'the sulfids as the chemico-physical law that each metal andchemical molecule has a definite latent heat of stability is effectiveand acts with metallic oxids and the oxids of metalloids, so as todissociate the component atoms and to form new molecules. It enablescharges composed of metallic oxids of iron and scheelite in combinationwith metallic aluminium to be dissociated and the new molecules-lime,corundum, and ferro-tungsten-boron-are formed. This reaction takes placeaccording to the following chemical equation: MA1-l-(FezO--QCaWOVl-BZOSz12Al2O3-l-2CaO-l-2(FeGWB4),mennaccanite(Fe'lUzOS-lezO3 is dissociated and the' newmolecule (EeGTi3:B6) is formed. Other complex oxidv molecules, likehuebnerite MuWo4, are also dissociated and form new definite crystallinemolecules of complex composition. Metallic suliids in combination withoxids also react perfectly. They are dissociated and new complexmolecules formed. Using molybdenite MOS2 in connection with FegOs andB202,y the molecule ferro molybdenum borid is formed FemBMog, as shownby the equation: 22AM- GFezO l 303203). 2 Al2sel l F912 MoSB-l-MAIOS).These compounds are not alloys- -that is, mixtures of metalsbut are truechemical molecules having deiinite composition and definite crystallinestructure, and the reduction of the oxids of these metals and metalloidsto form the compounds above named is a feature of the process of thepres ent invention.

lt Will be seen that With the employment of the drying-out of a charge,so as to positively remove all hygroscopic'or ordinarily presentmoisture therefrom, an almost end less number of metals, metalloids,alloys, and compounds can be obtained and that the process will resultin making each charge of a denite composition and have the charge in itsentirety composed of the contents of the chamber of the inner box orcasing With the result of accurate and perfect treatment in thereduction of the oxids, Whether of metalA or metalloids or whetherhaving a base of one metal or a base of two metals, thus assuring thereduction of metallic oxids and metalloids in a perfect manner and underconditions that Willenable the production'ot the desired metal,alloys,';and compounds to be made commercially practical.

What I regard as new, and desire to secure by Letters Patent, is-

l. 'The method of treating metallicv oxids with aluminium intheproduction of metals and metall'oids and alloys yand their compounds,Which consists in subjecting the tobe-treated charge comprisingaluminium in admixture With a metallic oxid reducible by aluminium to adrying by heat for removing the hygroscopic or ordinarily presentmoisture in a treatment preparatory to reduction, substantially asdescribed.

2. The method of treating metallic oxids with aluminium in theproduction of metals and alloys which consists in subjecting theto-be-treated charge comprisingv aluminium in admixture with a metallicoxid reducible by aluminium to a drying by steam heat for removal of thehygroscopic or ordinarily present moisture as a treatment preparatory toreduction, substantially as described.

3. The method of treating metallic oxids with aluminium in theproduction of metals and alloys'which consistsy in subjecting theto-be-treated charge comprising aluminium in admixture With a metallicoxid vreducible by aluminium both the aluminium and metallic oxid in thecondition of a iine powder or granule to a drying. by steam heat'forremoval of the hygroscopic or ordinarily present moisture as a treatmentpreparatory to reduction, substantially as described.

t. The method of treating metallic oxids with aluminium in theproduction of metals and metalloids, which consists in subjecting theto-be-treated charge comprising aluminium in admixture With a metallicoxid reducible by aluminium, to a drying by heat for re moving thehygroscopic or ordinarily present moisture and'dissociating the oxid andsulfid molecules from the to-be-treatedcharge in one operation as atreatment preparatory to reduction, substantially as described.

FREDERICK C. WEBER.

